What is Nelsons Syndrome?
This clinical condition results when a patient with an ACTH-producing pituitary adenoma undergoes bilateral adrenal gland removal (adrenalectomy). Approximately 15-25% of patients with Cushing’s disease treated with adrenalectomy will develop Nelson’s syndrome within 1 to 4 years. Because these ACTH-secreting tumors are typically aggressive and invasive in their growth, patients may develop large tumors resulting in visual loss, pituitary failure (hypopituitarism) and headache. These adenomas also secrete melanocyte-stimulating hormone, resulting in characteristic hyperpigmentation of the skin. ACTH blood levels are generally markedly elevated but hypercortisolemia is absent. Transsphenoidal surgery is generally the primary therapy, however cure is often difficult. Radiotherapy, preferably with stereotactic radiation, is effective in controlling tumor growth in the majority of patients who have residual tumor after surgery.
